Ski boot with latchable articulated leg holder

ABSTRACT

A ski boot with a leg-holding collar and constraining means to hold the skier&#39;&#39;s lower leg in a substantially fixed position relative to the ski, and means to release the constraints to allow the skier&#39;&#39;s heel to be raised and the skier&#39;&#39;s leg to pivot forward or backward relative to the ski.

451 Dec. 4, 1973 United States Patent [191 Rathmell 3,530,594 9/]970 Vogel 36/2.5 AL 3 722 I12 3/1973 36/2 5 AL SKI BOOT WITH LATCHABLE ARTICULATED LEG HOLDER [76] Inventor: Richard K. Rathmell, 12 Pine Tree Rd., Ramsey, NJ. 07446 Dec. 21, 1972 Primary ExaminerPatrick D. Lawson [22] Filed:

ABSTRACT App]. No.: 317,286

A ski boot with a leg-holding collar and constraining means to hold the skiers lower leg in a substantially fixed position relative to the ski, and means to release .0 n n 4 5 5 m 3 WR 15 "m2 n n 6 m h "mam 3.5 C d S L d U .m F 1]] 2 00 555 the constraints to allow the skiers heel to be raised and the skiers leg to pivot forward or backward relative to the ski.

[56] References Cited UNITED STATES PATENTS 13 Claims, 4 Drawing Figures PATENTEU DEC 4 I975 SHEET 2 SF 2 FIG; 5

SKI BOOT WITH LATCHABLE ARTICULATED LEG HOLDER CROSS REFERENCE See the accompanying applications entitled Ski Boot with Latchable Guided Heel Holder," Serial No. 317,287 filed Dec. 2l, 1972, and Crossed Double Layer Shoe Upper Ser. No. 317,285 filed Dec. 21, 1972.

FIELD OF THE INVENTION This invention deals with an improved ski boot that offers advantages for down-hill skiing plus conveniences for cross-country skiing.

BACKGROUND OF THE INVENTION At the present time, the boots, skis and bindings used for high-performance down-hill skiing are very different from the boots, skis and bindings used for crosscountry skiing. Nevertheless, a down-hill skier sometimes must encounter a horizontal or up-hill path, and a cross-country skier sometimes has the occasion to ski down-hill. It is not practical to change skis, boots and bindings for each situation encountered in a ski outing, but it is desirable and possible to have a boot which can be switched by convenient controls to facilitate either down-hill or cross-country skiing. Equally or more important, the range of adjustments possible with such a boot, and its greater comfort, make it advantageous for high-performance down-hill skiing.

For high-performance down-hill skiing, relatively rigid boots are preferred. It is important that a ski does not tilt or cant sideways under the skier; i.e., a geometric plane defined by the bottom of the ski should remain essentially perpendicular to a plane defined by the long center-line of the ski and some point in the skiers knee. It is also important that the skiers leg can be held relatively rigid or permitted to tilt forward and back only to a relatively limited extent, so that the skier simply can shift his body weight to put more pressure on the front tips of the skis or more pressure on the back ends of the skis. There is a variety-of ski boots now known with some articulation means to control the tilting of the leg forward or backward, and some have means for adjusting the tension orforce required to tilt the leg forward relative to the ski. Both thefront and back of the boot normally are held firmly by safety release bindings to the ski.

In contrast to the down-hill ski boots, the boots preferred for cross-country skiing are relatively soft to allow great freedom for the leg to pivot on the ankle joints. They are attached to the ski so that the heel can rise from the ski. The degree or motion allowed for the leg relative to the ski is substantially greater than that allowed by the present articulated down-hill ski boots. A good down-hill ski boot does not put much stress on the skiers ankle joint or associated muscles and tendons, whereas a good cross-country ski boot puts substantially all the stress on the skiers ankle joint and associated muscles and tendons.

It is evident that for good ski response to any slight force from the skier, the skiers foot and leg must not slide around loosely in the boot and the boot must be firmly attached to the ski. For a skier to apply a horizontal turning torque to the ski, the boot must transmit two horizontal forces in opposite directions. For a skier to apply a vertical torque, the boot must transmit two vertical forces. For instance, to make the front tip of the ski bear more heavily on the snow, a lifting force must be transmitted through the heel of the boot while a downward force is transmitted through the toe. These opposing vertical forces may be developed by opposing horizontal forces, a leg force pressing forward above the ankle and one pressing back at the heel. This patent application deals with the means of transmittingthese leg forces to the ski for improved down-hill skiing, and means of unlatching the force transmission systems to make the same boot better suited for horizontal or cross-country skiing. Separate co-pending applications deal with methods of transmitting heel forces and toe forces to the ski. The application dealing with heel forces describes a heel-holding shell which also is essential to the present application. However, in the present case, there are the additional requirements that the heel-holding shell must be structurally rigid and it must be equipped with pivot joints that essentially correspond to the skiers ankle joints.

DESCRIPTION OF THE INVENTION In accordance with the present invention, there is provided a ski boot consisting of a sole and an enlarged upper shell that can contain an articulated movable assembly in addition to the skiers foot, said assembly including a rigid vertically guided heel-holding shell, pivot points supported by the heel-holding shell on the right and left sides of the skiers ankle joints, and rigid structural members extending from the pivots to a legholding collar, with a system of means to constrain the leg and heel in a relatively fixed position in reference to the sole for down-hill skiing, and for cross-country skiing, means to unlatch the constraints and give the heel-holding shell substantial freedom to be raised and lowered relative to the sole and to give the leg-holding collar substantial freedom to move forward and backward relative to the sole.

One specific design utilizing the present invention is illustrated in FIG. 1. A rigid outer boot shell 19, appreciably larger than the skiers foot, is attached to a rigid sole 1, and there are the conventional extensions of the sole 2 and 23 to fit the conventional safety release bindings attached to the ski. A structurally rigid heelholding shell 3 has an inside shape and dimensions to conform to the shape and dimensions of the skiers heel, and means such as a strap 18 to keep the skiers heel held firmly within. Means are also provided to allow the heel-holding shell to slide up and down in a guided path, substantially vertically, but preferably along an arc of a circle, the center of this circle essentially corresponding with the principal joint 22 in the front of the skiers foot. The means to guide the heelholding shell can be matched projections and grooves, one set shown by 4. These can be dove-tail tongueand-groove shaped to prevent forward motion as well as side motion, or projections from both sides of the heel-holding shell can match grooves on the inside right side and inside left side of the boot sheell to serve the same purpose. Means are also provided to latch the heel-holding shell down, as with locking pin 5. This pin can be threaded or a variety of latching and unlatching devices could be substituted.

The structurally rigid heel-holding shell extends to pivots on the right and left sides of the skiers ankle joints.

Extending up from the pivots are two structurally rigid members 8 attached to a structurally rigid leg collar 13. The inside dimensions of this leg-holding collar preferably are adjustably padded to match the shape of the skiers leg. Means to open and close the leg collar and yet keep it structurally strong can consist of piano hinges 14 on each side with removable pins, or any of a variety of known fasteners.

Means are provided to constrain the leg-holding collar in a relatively fixed position for down-hill skiing. The forward constraint means, which also transmit forward leg forces to the ski, can be as illustrated in FIG. 1 with a flexible member 9 which resists elongation under tension. A wire cable, cord, or strap can be used. The back end of this flexible member is attached high in the back of the rigid boot shell, as shown by point 1 l, and the flexible member passes down and under a bearing 6 which is structurally fixed to the rigid heelholding shell. The front end of the flexible member 9 is attached to the leg-holding collar 13. Means to adjust or change the connections preferably are provided. Such means can include a threaded device 12, but any of a variety of means can be used on either the front or back of the flexible member 9. The flexible member may have some elastic properties engineered in to allow limited forward motion of the leg when the latching device is set for down-hill skiing. The flexible member may be an elastomeric material, such as rubber, with or without reinforcing cords to limit the stretch. Likewise, a coiled spring 10 can be compressively strained as shown, or a spring can be strained in tension.

With the forward constraint system as illustrated in FIG. 1, there is the advantage that the release of the single latching pin 5 releases both the heel and leg simultaneously.

A wide variety of constraint systems for the legholding collar and the heel-holding shell is possible within the scope of this invention.

As shown in FIG. 1, the means to constrain backward motion of the leg can include another flexible member that resists elongation in tension. This is attached to the leg-holding collar and to the front of the boot at a point that is structurally fixed relative to the rigid sole extension 23. Means are also provided to unlatch this constraint and allow the leg freedom to tilt back relative to the ski for cross-country performance. An eccentric quick-acting latch 21 is provided. Such a latch can be held in the down-hill position by a frictional grasp of the handle on the flexible member at point 20, or the handle can be released and thrown forward over the toe to allow the leg-holding collar freedom to move back. Obviously, a variety of latches or fasteners could be used within the scope of this invention, and adjustment features or elastic features as described for the forward constraint system could be used.

Normally, a skier will want means to keep snow and cold air out of the boot. A flexible pant leg 16 or special sleeve that tightens around the leg can be fastened on the bottom to the top of the rigid ski boot shell by means such as an elastic band 17. Other snaps and fasteners can be equally effective.

Obviously, some means must be provided to transmit forces from the front of the skiers foot 22 to the ski, but the means available are not the subject of the present invention.

FIG. 2 shows another possible constraint arrangement with compressive forces rather than tensile forces to transmit the forward forces of the leg to the ski. As shown, a coiled spring 24 with a lever arm 26 receiving the thrust will allow the lever arm to pivot downward around a pivot point essentially at the center of the coiled spring.

It can be seen that when the heel-holding shell is unlatched and raised, the thrust bearing 25 on the legholding collar also moves up, and greater leverage can be exerted on the Spring, in effect giving less resistance to the thrust. Preferably, the vertical position of the thrust bearing 25 can be adjusted on the leg-holding collar, using conventional means such as slotted holes and threaded hold-down fasteners. Moving the thrust bearing down to reduce the leverage can stiffen the forward constraint to whatever degree is desired for downhill skiing.

Another constraint arrangement is shown in FIG. 3. A coiled spring can work in compression to constrain forward movement of the leg. A quick-acting latching arm 21, able to turn on pivot point 27, this pivot point being structurally fixed relative to the sole of the boot, holds the coiled spring in compression against the legholding collar when the latching arm is as shown. By moving the latching arm forward and out over the toe of the boot, the spring can slide down to facilitate a cross-country style of skiing. The same latching arm simultaneously can control a tension member, as previously described, or preferably a pair of tension members on either side of the spring, to constrain the reverse movement of the leg-holding shell toward the back of the ski.

Another constraint arrangement, shown in FIG. 4, utilizes two tension members that function in direct tension. The member 9 that controls the forward motion of the leg is simultaneously latched down with the rigid heel-holding shell when latching pin 5 is in the locking position. When the latch pin is withdrawn, both the heel-holding shell and the leg-holding collar are simultaneously released. Member 9 as shown can include as parts a rigid strap 27 with one or more holes to accommodate the latching pin 5, an elastomeric section 28 with or without cord reinforcement to limit the stretch, and an adjustable fastener to couple the member to the leg-holding collar. The rigid strap 27 should have outside dimensions of width and thickness slightly smaller than the inside dimensions of a pocket sized to allow the strap to slide up and down when the skiers ankle joints are flexed. A coiled spring can be substituted for the elastomeric part.

Although a number of down-hill ski boots is commercially available with pivots at the skiers ankle joints, and it is possible to unlatch the forward constraining means in some of these boots, none of the boots known offers such a high degree of freedom of leg motion when unlatched, or means to simultaneously unlatch a heel-holding part and a leg-holding part, or means to simultaneously unlatch both the forward and backward constraining members.

None of the boots known ofi'ers the step-in convenience and simplicity of an oversized outer shell coupled with a superior firm fit for those parts of the boot that are used to transmit forces to the ski.

Many variations and modifications not specifically illustrated are possible within the scope of the present invention as defined by the following claims:

l. A ski boot including a sole attached to an upper shell and an articulated movable assembly consisting of a rigid vertically-guided heel-holding shell, pivot joints supported by the heel-holding shell on the right and left sides of the skiers ankle joints, and rigid structural members extending from thepivots to a leg-holding collar, with a system of means to fix or elastically constrain the positions of both the heel-holding shell and the leg-holding collar relative to the sole, and means to release the constraints to give the heel-holding shell substantial freedom to be raised and lowered relative to the sole and the leg-holding collar substantial freedom to move forward and backward relative to the sole.

2. A ski boot as in claim 1 where the means to constrain the position of the leg-holding collar relative to the sole includes members that resist elongation in tension, where one member can be tensioned behind the leg-holding collar and one member can be tensioned forward of the leg-holding collar, and means are provided for latching and unlatching the tension on each member.

3. A ski boot as in claim 1 where the means to constrain the position of the leg-holding collar and control forward motion relative to the sole consists of a flexible member that resists elongation when in tension, said member being attached to the boots upper shell, said upper shell being structurally rigid between the point where the member is attached and the sole, said flexible member passing downward and under a bearing device attached to the heel-holding shell, then passing upward to the leg-holding collar or supporting structure, wherein the heel-holding shell can be latched down and thereby maintain tension on the flexible member, or the heel-holding shell can be unlatched to give the heelholding shell substantial freedom to move vertically relative to the sole and the leg-holding collar substantial freedom to move forward and back relative to the sole.

4. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar and control forward motion relative to the sole includes a tension member that resists elongation in tension, means for latching both the heel-holding shell and one end of the tension member in a substantially fixed position relative to the sole, and means for unlatching both the heel-holding shell and the tension member to give the heel-holding shell substantial freedom to move vertically relative to the sole and the leg-holding collar substantial freedom to move forward and back relative to the sole.

5. A ski boot as in claim 1 where the means to constrain the position of the leg-holding collar and control backward motion relative to the sole includes a member that resists elongation when in tension, and means for latching attachment of the member so as to substantially prevent backward motion of the leg-holding collar, and means for unlatching so as to allow substantial backward motion of the leg-holding collar.

6. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar includes a compression member that resists deformation in compression, a tension member that resists elongation in tension, a latching device with means to hold a compressive force and a tensile force on these respective members and the leg-holding collar, and means to unlatch so that the leg-holding collar is not constrained by these members.

7. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar relative to the sole includes an elastic device with a pivoting lever that deforms relative to the torque applied, and a thrust bearing capable of pressing against the pivoted lever, arranged so that when the heel-holding shell is down the effective lever arm is short and substantial force is required to move the lever arm, but when the heel-holding shell is lifted from the sole the effective lever arm is longer and proportionately less force is required to move the leg-holding collar.

8. A ski boot as in claim 1 where the upper shell has a fixed opening large enough to permit the skiers foot to be inserted or withdrawn with the articulated movable assembly attached to the skiers heel and leg.

9. A ski boot as in claim 8 where means to keep snow and cold air out of the opening include a flexible material attached to the rim of the opening and the skiers leg.

10. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar includes an elastic member or members that resist deformation under stress, said system having elastic properties selected to allow a desired degree of forward and backward motion for the leg-holding collar relative to the sole.

11. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar relative to the sole includes means to adjust or change this position. I

12. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar relative to the sole includes means to adjust the amount of force required to move the constrained legholding collar either forward or backward.

13. A ski boot as in claim 1 where the heel-holding shellis part of an inner boot, this inner boot having a flexible sole under the ball of the foot, and the outer boot upper has inside dimensions large enough to allow the inner boot to rise in back, starting at the ball of the foot. 

1. A ski boot including a sole attached to an upper shell and an articulated movable assembly consisting of a rigid verticallyguided heel-holding shell, pivot joints supported by the heelholding shell on the right and left sides of the skier''s ankle joints, and rigid structural members extending from the pivots to a leg-holding collar, with a system of means to fix or elastically constrain the positions of both the heel-holding shell and the leg-holding collar relative to the sole, and means to release the constraints to give the heel-holding shell substantial freedom to be raised and lowered relative to the sole and the leg-holding collar substantial freedom to move forward and backward relative to the sole.
 2. A ski boot as in claim 1 where the means to constrain the position of the leg-holding collar relative to the sole includes members that resist elongation in tension, where one member can be tensioned behind the leg-holding collar and one member can be tensioned forward of the leg-holding collar, and means are provided for latching and unlatching the tension on each member.
 3. A ski boot as in claim 1 where the means to constrain the position of the leg-holding collar and control forward motion relative to the sole consists of a flexible member that resists elongation when in tension, said member being attached to the boot''s upper shell, said upper shell being structurally rigid between the point where the member is attached and the sole, said flexible member passing downward and under a bearing device attached to the heel-holding shell, then passing upward to the leg-holding collar or supporting structure, wherein the heel-holdinG shell can be latched down and thereby maintain tension on the flexible member, or the heel-holding shell can be unlatched to give the heel-holding shell substantial freedom to move vertically relative to the sole and the leg-holding collar substantial freedom to move forward and back relative to the sole.
 4. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar and control forward motion relative to the sole includes a tension member that resists elongation in tension, means for latching both the heel-holding shell and one end of the tension member in a substantially fixed position relative to the sole, and means for unlatching both the heel-holding shell and the tension member to give the heel-holding shell substantial freedom to move vertically relative to the sole and the leg-holding collar substantial freedom to move forward and back relative to the sole.
 5. A ski boot as in claim 1 where the means to constrain the position of the leg-holding collar and control backward motion relative to the sole includes a member that resists elongation when in tension, and means for latching attachment of the member so as to substantially prevent backward motion of the leg-holding collar, and means for unlatching so as to allow substantial backward motion of the leg-holding collar.
 6. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar includes a compression member that resists deformation in compression, a tension member that resists elongation in tension, a latching device with means to hold a compressive force and a tensile force on these respective members and the leg-holding collar, and means to unlatch so that the leg-holding collar is not constrained by these members.
 7. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar relative to the sole includes an elastic device with a pivoting lever that deforms relative to the torque applied, and a thrust bearing capable of pressing against the pivoted lever, arranged so that when the heel-holding shell is down the effective lever arm is short and substantial force is required to move the lever arm, but when the heel-holding shell is lifted from the sole the effective lever arm is longer and proportionately less force is required to move the leg-holding collar.
 8. A ski boot as in claim 1 where the upper shell has a fixed opening large enough to permit the skier''s foot to be inserted or withdrawn with the articulated movable assembly attached to the skier''s heel and leg.
 9. A ski boot as in claim 8 where means to keep snow and cold air out of the opening include a flexible material attached to the rim of the opening and the skier''s leg.
 10. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar includes an elastic member or members that resist deformation under stress, said system having elastic properties selected to allow a desired degree of forward and backward motion for the leg-holding collar relative to the sole.
 11. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar relative to the sole includes means to adjust or change this position.
 12. A ski boot as in claim 1 where the system of means to constrain the position of the leg-holding collar relative to the sole includes means to adjust the amount of force required to move the constrained leg-holding collar either forward or backward.
 13. A ski boot as in claim 1 where the heel-holding shell is part of an inner boot, this inner boot having a flexible sole under the ball of the foot, and the outer boot upper has inside dimensions large enough to allow the inner boot to rise in back, starting at the ball of the foot. 